Question

In $△$ABC, $\angle$A=100${}^o$ and AB = AC. Find $\angle$B and $\angle$C.

Answer 1

$AB=AC$

$\angle B=\angle C$ [Angles opposite to equal sides are equal]

In $△ABC$,

$\angle A+\angle B+\angle C={180}^o$

${100}^o+2\angle B={180}^o$

$\angle B={40}^o$

Therefore,

$\angle B=\angle C={40}^o$